HAMR: Over 2 Tb/inchand Onwards

As discussed above, SMR and TDMR technologies combined are expected to increase the areal density of HDD platters by approximately 10% to 20% compared to platters used inside of today’s hard drives. Seagate has done a lot to make SMR viable for a variety of applications and we are yet to see the fruits of TDMR. However, keeping in mind physical limitations of PMR and SMR as well as high-cost of helium-filled HDD tech (as of today, according to Seagate), a new magnetic recording technology is needed. Yes, we are (finally!) talking about HAMR.

Seagate says that its HAMR heads heat media to approximately 450°C using a laser with 810nm wavelength and 20mW power. Seagate’s current internal HAMR-based HDD have an areal density of about 2 Tb/inch2, which is considerably higher when compared to today’s PMR or SMR HDDs. Potentially, this means that Seagate can increase the capacity of hard drives by 2x just by employing the technology. In reality, not everything is that easy.

The device, which heats storage media, is called a near-field optical transducer (NFT). Hard drive makers use gold as the primary NFT material due to its superior optical properties. On the other hand, gold has a comparatively low mechanical strength and such NFTs may experience reflow at elevated temperatures resulting in deformation of the NFT shape. A deformation in shape can reduce coupling efficiency and reduce the amount of light energy transferred to the storage medium, which essentially means a damaged hard drive. This is why Seagate and other makers of HDDs have researched and patented a variety of materials (alloys based on gold, to be precise) for NFT for years now. Seagate does not reveal the alloy it uses for NFTs for now.

Nonetheless, Seagate stresses that when it ships its first HAMR-based HDDs for evaluation (in 2017) and then for commercial systems (in 2018), they will be rated to work for a long time, just like today’s hard drives. Seagate does not reveal any data about its HAMR-based HDDs for now, but claims that they can offer several writes per drive per day over five years, which suggests pretty high reliability. Eventually, client drives will also rely on HAMR, but those HDDs are pretty far away from us at this point.

The HDD maker is not disclosing any details when it comes to transducer materials. Apart from a durable NFT, HAMR-based HDDs will need a new head (featuring a heater, a writer, and several readers to mitigate the ITI effect), which means a lot of work both on hardware on multiple fronts. In the end, HAMR-based hard drives will aim to add both capacity and performance. But to make everything work, Seagate will have to develop a rather robust platform, which will involve complex controllers in addition to new materials and a number of other things.

It should be noted that HAMR is a challenge for the whole industry, not just for Seagate. As a result, as soon as the industry figures out how to make HAMR-based hard drives as reliable as traditional HDDs, the technology will be used right across the board.

New 10K and 15K RPM HDDs Incoming Conclusion and Sources
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  • Ushio01 - Wednesday, July 6, 2016 - link

    I wonder how much of this will ever reach market? as SSD's take over ever more of the storage market the remaining HDD manufacturers will be required to spend ever more on R&D while dealing with shrinking revenue.
  • DanNeely - Wednesday, July 6, 2016 - link

    The consumer HDD market is slowly imploding, but while it's roughly half of all drives sold that's not where the money is. The Enterprise HDD market is doing better. Sales are down a bit; but while Seagate/WD/Toshiba don't break the two segments of enterprise drives out, it's probably from SSDs chewing into 10/15k drives in servers not the high capacity 3.5" drives used for bulk storage. Seagates comments about the next gen of 15k drives potentially being the last tends to back this up, since they're talking about multiple generations of other drive types.

    Bulk data storage will stay with spinning rust until the price per GB crosses over in SSDs favor. Estimates I've seen on that a year or so ago were looking at 2025; but there's a fair amount of speculation there since the results of a half dozen generations of tech in each platform are somewhat speculative.
  • Anato - Wednesday, July 6, 2016 - link

    That patent [1] is clear example how current patent system is out of control and not useful to society at large. Short recap, patents original idea was to give temporal monopoly to inventor who disclosed his invention. There was no right to own anything you invented, but it was seen that disclosing the invention would ultimately benefit society who, after temporal monopoly, could use the invention.

    Now opposite is true, there is nothing useful disclosed in Seagates patent! But we grand Seagate sole ownership to use Gold with Cu, Rh, Ru, ... or Mo in concentrations of 0.5-30% in HAMR NFT. How does this benefit us?

    Of course Seagate can't stop WD to use same alloys as WD have similar patents to sue back, but they both can stifle smaller competitors. I don't think there will be any more competitors in HDD space, but same applies to other fields and their patents.

    [1] http://www.google.com/patents/US8427925

    [Disclosure, I didn't read full patent application, did cursory review and didn't find anything of value]
  • Zak - Wednesday, July 6, 2016 - link

    I was wondering why HDs never broke the 7500rpm and 15000rpm barriers.
  • DanNeely - Wednesday, July 6, 2016 - link

    For consumer devices: noise. 10/15k HDDs are obnoxiously loud like an >40x CD or >16x DVD drive; except that they're spinning constantly not just for the few minutes it takes to read/write them. On the enterprise side, I'd guess implementation difficulty; probably due to vibrations was the limiting factor. If not mechanical strength of the platters themselves was probably the issue. Top end centrifuges can go to at least 70k RPM; but can be built much more heavily than a thin platter can.
  • metayoshi - Wednesday, July 6, 2016 - link

    Not just noise, but heat. In a constrained system like a laptop or desktop, the spindle and vibrations cause a ton of heat to be generated. Just look at WD's last consumer 10k drive, the 1 TB Velociraptor. It's a 2.5" drive that comes with its own heatsink for 3.5" bays. You definitely can't put that in a laptop, and it hits a market in the desktop space which has pretty much been taken over by SSDs.
  • piasabird - Wednesday, July 6, 2016 - link

    Still using hard drives. No reason to switch when hard drives are so cheap. When I watch TV on the Internet, It still works so no reason to change.
  • pavag - Wednesday, July 6, 2016 - link

    Kurzweil curse.

    Nobody accounts the relative speed of price reduction. SSD will get cheaper per gigabyte than SSD before 2020.

    We will never see HDMR HDD. And there is a chance we will not even get HAMR.

    And article speculating about the date when SSD will beat HDD for price per gigabyte would be interesting.
  • serendip - Friday, July 8, 2016 - link

    I'm not sure about this. On my laptop, I've got a 120 GB SSD I got ages ago along with a recent 2 TB drive. Both cost about the same when new. I think HDDs will continue to get bigger and cheaper faster than SSDs, at least until some new process tech allows for very high flash densities and low production cost.

    The main issue is price. There are still lots of users (like me) who can't afford huge multi-TB SSDs to hold everything, so they have to make do with a boot SSD and a storage HDD.
  • jabber - Wednesday, July 6, 2016 - link

    So you didn't bother to ask why Seagate's HDD reliability has nosedived since the floods a few years back?

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